Hydraulic power sources are used more and more to operate power tools, and particularly power tools requiring high pressure. Hydraulic drive motors can be used to energize concrete drills and concrete boring apparatus, concrete saws, and, also, concrete crushers. The referenced U.S. Pat. No. 4,932,597, by the inventor hereof, illustrates a concrete crusher which can be clamped around a concrete wall structure, for example, to crush the wall structure into pieces which can be handled more easily. The referenced U.S. Pat. No. 4,964,434, by the inventor hereof, describes a suitable hydraulic valving system to control hydraulic pressures being applied to hydraulically operated tools; and the referenced U.S. Pat. No. 4,923,344 describes a coupling element, especially adapted for coupling and uncoupling concrete or rock boring or milling tools to a drive source.
The hydraulic power or energy supply apparatus, generating hydraulic pressure, is normally separate from the tools being used, and connected to the tools or apparatus units by high-pressure hoses. Increasing pressure requirements of hydraulically operated tools and units call for larger hydraulic power and pressure supply units or systems. The power supply systems then become large and heavy. If the tools are to be operated, for example, in a multi-level building, transportation of such power supply units to upper floors becomes difficult.